nerfing HA but not Cav will mess up the balance and it will only end up making Cav more OP except mounted ranged. Mounted ranged is very much the only class that can counter Lancer/1H Cav beside foot ranged. HA is fine as it is , doesn't need a nerf or anything. people who is whining for HA nerf is definitely infantry class. nerfing a class because you don't like it is just retarded. In real life the power of the bow and the accuracy with which the Mongols could shoot it from horseback made them an almost unstoppable power during invasion of mongols. They owns literally everyone especially knights.
Firing high-powered composite bows from horseback. Not only were they fast-moving, but they could kill you from 100 yards away. That's tough to counter no matter how well-organized your forces are. HA are OP, they rode up, shot arrows at you then rode off. pick smaller units caught in the open and tear them to pieces
if you are going to nerf HA nerf all Cav as well otherwise its going to be a very unbalanced Cav game.